It is now commonly accepted that the vision impairing disease known as cataracts can be alleviated by surgically replacing the natural lens of the eye with an artificial intraocular lens.
The anatomy of the eye is shown schematically in FIG. 2. The cornea 2 forms the front surface of the eye and connects with the cilliary muscle 3 from which iris 4 extends. Iris 4 divides the front portion of the eye into the anterior chamber 5 in front of iris 4 and the posterior chamber 6, behind iris 4. The pupil 7 is the aperture at the center of iris 4 through which light passes to posterior chamber 6 and onto the back of the eye (not shown).
The condition of cataracts is characterized by the clouding or opacification of the natural lens of the eye so that the amount of light which reaches the retina is substantially reduced or completely eliminated. The natural lens of the eye is encased in a capsular bag 8, as shown in FIG. 2, which is supported by suspensory ligaments, or zonules, 9 from cilliary muscle 3.
During intraocular lens surgery, the natural lens of the eye is removed by a variety of methods well known to those skilled in the art. The front surface of the capsular bag is removed so that an artificial intraocular lens may be placed in capsular bag 8. The eye shown schematically in FIGS. 2, 3 and 5 through 8 has the natural lens and the front surface of capsular bag 8 removed so that the eye is ready for the insertion of the intraocular lens.
There are a wide variety of artificial intraocular lenses that have been used to replace the natural cataract lens. One particularly desirable style of lens is designed to fit completely within capsular bag 8. The type of lens suitable for insertion in the capsular bag is shown in FIG. 4, identified by reference character 10. This lens has two principal parts: a medial, light-focusing body 14 (also called the optic) made of a nontoxic plastic material which will replace the natural lens of the eye and focus light on the retina, and haptic support portions 16 and 18 which extend from optic 14 to the anatomy of the eye and provide means for fixing and holding optic 14 in its proper position within the eye.
Referring again to FIG. 2, there is shown an incision 12 at the edge of the eye through which the lens will be inserted. The patient is usually lying on his back with the doctors standing facing the top of the patient's head. The incision would be made at a position called the superior part of the eye, and the intraocular lens is inserted from the superior portion of the eye toward the inferior portion of the eye. The first haptic to be inserted into the eye is called the inferior haptic. The second haptic to be inserted into the eye is called the superior haptic. This terminology of inferior position and superior position is generally used in the industry, and inferior positions are those spaced further away from the entrance incision, and superior positions are those spaced closer to the entry incision.
When a surgeon inserts an intraocular lens 10, like that shown in FIG. 4, into the eye through incision 12, the inferior haptic is placed against the inferior internal surface of capsular bag 8. The lens is then maneuvered into the capsular bag, and then the superior haptic is placed in capsular bag 8. Many surgeons have difficulty placing the superior haptic in capsular bag 8, because it is very hard to reach and it cannot be easily visualized by the surgeon. Thus, even though the superior haptic may appear to be placed in the superior side of capsular bag 8, it is very difficult to confirm that that is actually the case. It would be desirable if there were an insertion tool that would easily, quickly and reliably permit the surgeon to be assured that he had placed the superior haptic of the lens in capsular bag 8.